Elbows (Reduced Bends) are pipe fittings used for varying pipe diameters. Typically, the forming process involves necking down, expanding, or a combination of both necking and expanding. For certain sizes of elbows, stamping forming may also be employed.

Contraction/Expansion Forming

The reduction forming process for male and female ends involves placing a billet with a diameter equal to the male end of the male and female ends into a forming die, then compressing it along the axial direction of the billet to allow the metal to move and shrink into shape within the die cavity. Depending on the size of the diameter change of the reducing pipe, it is divided into single-stage or multi-stage forming.

b. Stamping成形

In addition to producing elbows using steel pipes as raw materials, elbows of certain specifications can also be manufactured using steel plates via the stamping forming process. The shape of the stamping die used for stretching is designed based on the inner surface dimensions of the elbows, and the steel plates after blanking are stamped and stretched into shape using the die.